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The Mind Body Precipitants of Panic Disorder

Healthy Concept, Spirit, Body And MindPanic Disorder (PD) is a prevalent disorder causing distress, dysfunction and disability to those affected. People with PD have been found to have higher amounts of negative affect, emotional reactivity, (Shurick & Gross, 2012), and threat related attention bias (Abend & Bar-Haim, 2013).

Homeostatic dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and its role in releasing stress hormones such as cortisol has been vigorously studied, and is thought to be a precipitant of PD (Abelson, Khan, Liberzon, & Young, 2007).

However, discriminating views are developing which indicate a divergence between the psychological and physiological precipitants of general anxiety and symptoms of panic. While general anxiety appears to be associated with distal threats or anticipation, PD has been linked with more proximal stressors and activation of the sympathetic neural pathways (Graeff  & Zangross Jr. 2010).

Cognitive Affective Mechanism of Panic Disorder

Those with PD may experience a threat related attention bias, which leads individuals to interpret ambiguous events and stimuli as threatening or dangerous (Abend & Bar-Haim, 2013).

Individuals with PD have a propensity for focusing on stimuli they perceive as threatening or fearful. These threats could be external events or internal somatic processes, such as heart rate, which the PD client self-monitors with hypervigilance.  White et al. (2011) found that people conditioned to attend towards a threatening situation often began interpreting all ambiguous stimuli as threatening.

Neural imaging has now made it possible to examine the neural reactions to various stimuli for those with mental disorders (Shurick & Gross, 2013).

Using functional magnetic resonance imaging (FMRI), Kircher et al. (2013) found there was no difference between PD and healthy subjects (HS) in their acquisition of conditioned aversive stimuli and conditioned excitatory stimuli.

The results also indicated there was no group x time interaction for activity in the inferior frontal gyrus, amygdala, hippocampus, and medial and lateral prefrontal cortex.

Those diagnosed with PD did have higher levels of negative effect and arousal than healthy subjects.  Their findings lend support to the emotional hyperactivity hypothesis for those with PD. The results are in contrast to the belief that PD is the product of maladaptive associative learning, in which fears are learned and applied to related stimuli (Lissek, Rabin, Heller, Lukenbaugh, Geraci, & Pine, 2010).

Sensitivity is a cognitive/affective mechanism of PD related to internal monitoring of bodily functions.  People reporting symptoms of PD, will often catastrophize bodily sensations (Gallagher et al., 2013).  According to the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5), PD patients often interpret mild physiological symptoms to mean they have a serious medical problem. These interpretation may be more prevalent in those who have had a history with serious illness such as asthma, seizure disorder or cardiovascular disease (APA, 2013).

Another cognitive mechanism associated with PD is self-efficacy.  Self-efficacy is the belief in oneself to achieve outcomes they deem successful.  PD Patients with strong self-efficacy develop an internal locus of control permitting them to believe they have the ability to control their symptoms of panic.  Helping patients develop cognitive mastery over the somatic symptoms of PD, and the ability to cope with these symptoms, has been shown to be one of the most salient factors for recovery in the latter stages of treatment (Gallagher et al., 2013).

Emotions originating panic, fear, and anxiety are related to perception of threat.  Graeff and Zangross Jr. (2010) suggest two different types of threats; distal and proximal. With distal threat, the individual engages a risk assessment based behavior, wherein danger is suspected or uncertain, resulting in anxiety.  Proximal threat on the other hand, is evoked when danger is near and recognized, engaging the flight or fight response, and activation of the sympathetic nervous system.

The authors suggest that general anxiety disorder (GAD) is connected to distal threat, whereas PD is more commiserate with proximal threats.

Physiological Precipitants of Panic Disorder

The hypothalamic pituitary, adrenal (HPA) axis responds to stress from the hypothalamus by releasing corticotrophin-releasing hormone (CRH) , which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH).  Circulating ACTH in turn triggers the release of cortisol by the adrenal cortex (Plag et al., 2014).

The negative feedback loop is completed when cortisol returns to the hypothalamus and pituitary gland, resulting in the reduction of ACTH and CRH release. (Marieb & Hoehn, 2007).

In a systematic review by Abelson, Khan, Liberzon, and Young (2007), the authors found that dysregulation of the HPA axis is thought to be the result of overcompensation to novel stimuli and hypersensitivity to cues within an individual’s environment, which result in elevated endocrine secretions of cortisol and other stress related hormones.

This increased activity in the HPA axis is found in healthy individuals as well as those with PD. However, individuals with PD were found to be more sensitive to acute contextual stressors, which lead to HPA axis activation (Abelson, Khan, Liberzon, & Young, 2007).

Acute HPA axis activation was explored in a study conducted by Garcia-Leal et al. (2005). The authors used three groups of participants; a PD symptomatic group, a PD drug-treated asymptomatic group, and a healthy control group. The three groups were to give a simulated public speech (SPS). Prior to the SPS, the PD symptomatic group had significantly higher levels of salivary cortisol than the asymptomatic PD and control groups.

In addition, two testing instruments measuring anxiety were administered throughout the process; the Visual Analog Mood Scale (VAMS) and the Bodily System Scale (BSS). A positive and significant correlation was made between all three groups in relation to the VAMS, BSS, and salivary cortisol.  However, towards the end of the speech, cortisol levels dropped for all three groups as they habituated to the experience, indicating that HPA axis activation was tied more to anticipatory anxiety.

In a review by Graeff and Zangrossi Jr. (2010), the authors cited studies where panicogenic agents, such as CO2 and lactate did not activate the HPA axis or increase cortisol levels.

In addition, their review also covered animal studies involving rats, where electro-stimulation of the periaqueductal grey matter and maze escape exercises did not increase stress hormones in the plasma cortisol.

The authors suggest that panic and anxiety are different emotional states. These two states react differently to proximal and potential threats. Their contention was that while GAD activates both the HPA axis and sympatho-adrenal axes, PD’s major activation is primarily directed towards the sympathetic axes, with smaller effect on the HPA axis (Graeff & Zangrossi Jr., 2010).

Petrowski et al. (2013) assessed HPA axis response and cortisol levels in both PD patients and healthy controls, when exposed to stress, using the Trier Social Stress Test (TSST).  Although both groups did show an increase in cortisol during the TSST, patients in the PD group showed significantly lower levels of cortisol elevation.

The authors postulated the reason for the cortisol attenuation in the PD patients could be because of habituation by the adrenocortical system, as a result of the constant stress perception by those experiencing symptoms of panic frequently.

The stress response of the sympathetic nervous system is more directly related to the symptoms of PD.  Through the release of the catecholamines epinephrine and norepinephrine from the adrenal cortex, the sympathetic stress response raises blood pressure and increases heart rate (Plag et al., 2014).

The hypothalamus activates the sympathetic nervous system for the fight or flight response.  It does this by sending impulses by way of the preganglionic sympathetic efferent fibers to the adrenal cortex, where epinephrine and norepinephrine are released.

This autonomic response to stress is relatively short-lived and immediate, while the adrenocortical response involving the release of cortisol is a more long-term response (Marieb & Hoehn, 2007).

Conclusion

PD is an anxiety disorder with neurobiological and psychological origins.  Recent studies suggest activation of the HPA axis and subsequent release of the stress hormone cortisol has limited effect on the acute stimulation of the sympathetic nervous system that is associated with PD.

However, HPA axis dysregulation has been linked with anticipatory anxiety, and is associated with other anxiety disorders such as GAD.  The research indicates maladaptive cognitions associated with threat related attentional bias is correlated with emotional reactivity. Those reporting higher levels of emotional reactivity are more likely to process acute stressors through the fear network, leading to hypothalamic activation of the sympathetic nervous system and subsequent release of norepinephrine from the adrenal cortex.

Steven Powden received his master’s degree in clinical psychology from Forest Institute of Professional Psychology in Springfield, MO. He previously worked as a mental health therapist at Hamilton Centers Inc. and currently teaches psychology courses at Olney Central College in Olney, IL. Steven has specialized interest in integrative medicine, anxiety, and depressive disorders.

 

 

 

 

References

Abelson, J. L., Khan, S., Liberzon, I., & Young, E. A. (2007). HPA axis activity in patients with  panic

disorder: Review and synthesis of four studies. Depression and Anxiety, 24, 66-76.

Abend, R., & Bar-Haim, Y. (2013). Threat-related attention bias in the early stages of cognitive- behavioral therapy action for panic disorder. Biological Psychiatry, 73, 1041-1042.

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders   (5th ed.). Washington, DC: Author.

Gallagher, M. W., Payne, L. A., White, K. S., Shear, K. M., Woods, S. W., Gorman, J. M., &  Barlow, D. H. (2013). Mechanisms of change in cognitive behavioral therapy for panic      disorder: The unique effects of self-efficacy and anxiety sensitivity. Behavioral Response  Therapy, 51, 767-777.

Garcia-Leal, G., Parente, A. C. V. B., Del-Ben, C. M., Guimaraes, F. S., Moreira, A. C., Elias, L. K., & Graeff, F. G. (2005). Anxiety and salivary cortisol in symptomatic and non- symptomatic panic patients and healthy volunteers performing simulated public speaking. Psychiatry Research, 133, 239-252.

Graeff, G. G., & Zangross Jr., H. (2010). The hypothalamic-adrenal axis in anxiety and panic.  Psychology and Neuroscience, 3, 3-2.

Kircher, T., Arolt, V., Jansen, A., Pyka, M., Reinhardt, I., Kellermann, T., … & Straube, B.     (2013). Effect of cognitive-behavioral therapy on neural correlates of fear conditioning in         panic disorder. Biological Psychiatry, 73, 93-101. http://dx.doi.org/10.1016/j.  biopsych.2012.07.026.

Lissek, S., Rabin, S. Heller, R. E., Lukenbaugh, D., Geraci, M., & Pine, D.S. (2010).    Overgeneralization of conditioned fears as a pathogenic marker of panic disorder.  American Journal of Psychiatry, 167, 47-55.

Marieb, E. N., Hoehn, K. (2007). Human anatomy and physiology. San Francisco, CA: Pearson, Benjamin, and Cummings.

Petrowski, K., Wintermann, G. B., Schaarschmidt, M., Bornstein, S. R., & Kirschbaum, C.  (2013). Blunted salivary and plasma cortisol response in patients with panic disorder under psychological stress. International Journal of Psychophysiology.88, 35-39.

Plag, J., Gaudlitz, k., Schumacher, S., Dimeo, F., Bobbert, T., Kirschbaum, C., & Strohle, A.           (2014). Effect of combined cognitive-behavioral therapy and endurance training on  cortisol and salivary alpha-amylase in panic disorder. Journal of Psychiatric Research, 58, 12-19.

Shurick,A. A., & Gross, J. J. (2013). Emotional reactivity and regulation in panic disorder:        Insights from a functional magnetic resonance imaging study of cognitive behavioral           therapy. Biological Psychiatry, 73, 5-6.

White, L.K., Sunway, J. G., Pine, D. S., Bar-Haim, T., & Fox, N. A. (2011). Cascading effects: the effects of attention bias to threat on interpretation of ambiguous information. Behavior Therapy, 49, 244-251.

 

 

 

 

The Mind Body Precipitants of Panic Disorder